In the past, a technique in which a radio terminal switches a communication path between a mobile communication network and a wireless LAN has been proposed (for example, see Non-Patent Literature 1). A communication path is established between a radio terminal and a core network, and switching in access point name (APN) units (or bearer units) can be performed.
The switching of the communication path is performed by network selection of selecting a network and traffic steering of routing traffic. In long term evolution (LTE), a mobile communication network is referred to as an evolved universal terrestrial radio access network (E-UTRAN), and a core network is referred to as an evolved packet core (EPC).
The radio terminal determines whether or not switching is performed on the basis of whether or not first information on a mobile communication network side satisfies a first condition and whether or not second information on a wireless LAN side satisfies a second condition. The first information is, for example, a measurement result (RSRPmeas) of a reference signal received power (RSRP) and a measurement result (RSRQmeas) of the reference signal received quality (RSRQ). The second information is, for example, a wireless LAN channel utilization value, a wireless LAN backhaul value, a received signal strength indicator (RSSI).
Determination parameters for determining whether or not the communication path between the mobile communication network and the wireless LAN is performed are notified from a base station provided in a mobile communication network to the radio terminal. As the determination parameters, there are individual parameters which are notified to the radio terminal and broadcast parameters which are broadcast to the radio terminal.